Gareth Southgate has condemned the "ridiculous treatment" of England defender Harry Maguire, labelling the unrelenting criticism a "joke".
The Manchester United centre-back won his 59th cap as a substitute in England's 3-1 friendly win in Glasgow on Tuesday but his performance was marred by an own goal.
Maguire, named in the European Championship team of the tournament two years ago, has become a target for abuse after struggling for form and game-time at Old Trafford.
But he remains an integral part of Southgate's England squad.
The 30-year-old made his first start of the season in Saturday's 1-1 draw against Ukraine in a Euro 2024 qualifier.
However, he was mocked mercilessly when brought on at half-time against Scotland three days later.
England boss Southgate said he had no complaints about the Scottish fans' behaviour, but added that it was a "consequence of ridiculous treatment of him for a long period of time".
"It's a joke," he said. "I've never known a player treated the way he is -- not by the Scottish fans, by our own commentators, pundits, whatever it is.
"They've created something that's beyond anything I've ever seen.
"He's been an absolute stalwart for us in the second-most successful England team for decades. He's been an absolutely key part of that."
England fans chanted the defender's name throughout the second half at Hampden Park, bellowing out "Harry Maguire, he's winning 3-1" after Harry Kane added to Phil Foden and Jude Bellingham's first-half goals.
Asked how Maguire was after the match, Southgate, who described the own goal as "unfortunate", said: "He's good, he's great. We've had a good win, he's been a big part of that."